I really like the suggestions of …
[name_u]Remington[/name_u], [name_u]Allison[/name_u], and … [name_u]Cameron[/name_u]
[name_u]Remington[/name_u], [name_u]Allison[/name_u], and … [name_u]Evelyn[/name_u]
[name_u]Remington[/name_u], [name_u]Allison[/name_u], and … [name_u]Fallon[/name_u]
[name_u]Remington[/name_u], [name_u]Allison[/name_u], and … [name_f]Jocelyn[/name_f]
[name_u]Remington[/name_u], [name_u]Allison[/name_u], and … [name_m]Kerrigan[/name_m]
[name_u]Remington[/name_u], [name_u]Allison[/name_u], and … [name_u]Leighton[/name_u]
[name_u]Remington[/name_u], [name_u]Allison[/name_u], and … [name_u]Morgan[/name_u]
Here are some additional suggestions …
[name_u]Remington[/name_u], [name_u]Allison[/name_u], and … Aymeline
[name_u]Remington[/name_u], [name_u]Allison[/name_u], and … [name_f]Celestine[/name_f]
[name_u]Remington[/name_u], [name_u]Allison[/name_u], and … Eadlyn
[name_u]Remington[/name_u], [name_u]Allison[/name_u], and … [name_f]Evangeline[/name_f]
[name_u]Remington[/name_u], [name_u]Allison[/name_u], and … [name_f]Gillian[/name_f]
[name_u]Remington[/name_u], [name_u]Allison[/name_u], and … [name_f]Jillian[/name_f]
[name_u]Remington[/name_u], [name_u]Allison[/name_u], and … [name_u]Kiernan[/name_u]
[name_u]Remington[/name_u], [name_u]Allison[/name_u], and … [name_m]Lincoln[/name_m]
[name_u]Remington[/name_u], [name_u]Allison[/name_u], and … Madgalen
[name_u]Remington[/name_u], [name_u]Allison[/name_u], and … [name_f]Magdalene[/name_f]
[name_u]Remington[/name_u], [name_u]Allison[/name_u], and … [name_u]Marian[/name_u]
[name_u]Remington[/name_u], [name_u]Allison[/name_u], and … [name_f]Ottoline[/name_f]
[name_u]Remington[/name_u], [name_u]Allison[/name_u], and … [name_f]Rhoswen[/name_f]
[name_u]Remington[/name_u], [name_u]Allison[/name_u], and … Tamaryn
[name_u]Remington[/name_u], [name_u]Allison[/name_u], and … [name_f]Thomasin[/name_f]
[name_u]Remington[/name_u], [name_u]Allison[/name_u], and … [name_f]Thomasine[/name_f]
[name_u]Remington[/name_u], [name_u]Allison[/name_u], and … Troian
The ones I think work best and meet ALL of your criteria are …
[name_u]Remington[/name_u], [name_u]Allison[/name_u], and … [name_f]Jocelyn[/name_f] (distinct and blendable)
[name_u]Remington[/name_u], [name_u]Allison[/name_u], and … [name_u]Kerrigan[/name_u] (a blendable surname as first name)
[name_u]Remington[/name_u], [name_u]Allison[/name_u], and … Madgalen (distinct, yet sweet)
[name_u]Remington[/name_u], [name_u]Allison[/name_u], and … Tamaryn (most unique)
[name_u]Remington[/name_u], [name_u]Allison[/name_u], and … [name_f]Thomasin[/name_f] (unique, yet distinctly well rounded in a potential sibset)
Let us know if we can help you with more suggestions!